1. Field of the Invention
The invention relates to railway rolling stock and consists particularly in a radial axle car truck with stably supported side frames.
2. The Prior Art
F. W. Sinclair U.S. Pat. No. 2,981,208 discloses railway trucks in which the transverse framing members are supported on separate side frames by chevron-shaped rubber and metal springs and in which the side frames are supported rigidly on the journal boxes. In the Sinclair patent, each side frame is of box section with its central portion depressed between its end portions which are integral with the journal boxes, and with the chevron spring devices on top of the depressed center portion adjacent the intersections of the end portions and the depressed center portion. Since the side frames of Sinclair are supported directly on the axles, the side frames are not subject to substantial tipping as a result of transverse forces applied to them even though the bolster supporting chevron spring devices are supported on the side frames at a higher level than the axles. In radial axle trucks such as those disclosed in Herbert Scheffel U.S. Pat. Nos. 4,067,261, 4,067,262 and 4,136,620 and Robert L. Bullock Pat. No. 4,111,131, the side frames are mounted on the journal boxes by means of elastomeric pad devices constructed to yield in shear horizontally to accommodate sufficient yawing movements of the respective axles to permit the respective axles to assume radial positions on curved track, but in each of these truck arrangements, the bolster is supported in the conventional way on the side frames by springs seated at a very low level on the bottom chord of truss side frames. R. B. Cottrell U.S. Pat. No. 2,743,682 discloses a truck of the separate side frame type in which the side frames are integral with the journal boxes and of box section depressed between the journal boxes and formed with upwardly open spring pockets in their depressed center section for a group of upright coil springs on which the ends of a transverse bolster are carried, each side frame also being formed with upstanding guide abutments slidably engaging cooperating guide surfaces on the bolster to hold the bolster and side frames in trammed relation with each other. Since the side frames are stably supported directly on the axle journals without any yieldable means between the journal bearings and the side frames, the principal purpose of the pockets of Cottrell is to provide nearly as low a level for the bolster supporting springs as would be provided in a conventional freight car truck having side frames of the queen-post truss type.